Giga-tronics 80350A, Operation & Maintenance Manual

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Series 8035XA Peak Power Sensors
2-4 Manual 21568, Rev. F, March 2008
2.2.3 Zeroing
Zero the sensor before taking critical measurements in the bottom 10 dB of the peak power
sensor’s dynamic range. For standard peak power sensors, this level is -10 dBm.
When making dual channel power measurements, zero the sensors whenever another sensor
is attached or disconnected. Use the following steps:
1. Turn off the RF source.
2. Press [CAL/ZERO].
The sensors will zero automatically. The 8540 power meters detect when a sensor is attached
to the calibrator port. When a sensor is not attached to the power sweep calibrator, the power
meter automatically initiates the zeroing procedure (if only one sensor is connected to the
meter). Be sure to deactivate the RF source for zeroing. Leaving the sensor attached to your
measurement test ports during zeroing properly accounts for test setup ground noise and metal
to metal contact thermal EMF.
The 8035XA Series EXT trigger port is on the back of the sensor, not the power meter. A set of
three SMB(f) to BNC(m) cables are included with each 8035XA Series sensor. The EXT trigger
input impedance is 110 k
Ω
. This allows you to use TTL level signals without damaging the input
circuit. However, the input impedance match might cause triggering line reflections and
potential false triggering when fast (50
Ω
) trigger sources are used.
This can be resolved by setting the EXT trigger level (see Figure 2-1).
The CW power measurement mode is also selected in the Peak Sensor Setup menu. CW
measurements are automatically performed on a continuous basis.
Figure 2-3: 8035XA Sensor Timing Diagram
This is a pproximately 0.0 ns delay.
A built in delay line provides at least
20 ns look-ahead capability.
Sample Delay Pulse
10 s
µ
Delay
58542 VXIbus Power Meter SCPI Compatible Commands
OUTPUT @Pwr_MTR;SENS1:TRIG:SOUR INT
OUTPUT @Pwr_mtr, SENS1: TRIG: DEL 10E-06
WAIT 200
OUTPUT @Pwr_mtr, MEAS1?
ENTER @Pwr_mtr: Peak_pwr_rdg
! Selects Internal Triggering
! Sets Sample Delay Position to 10 s
! Wait 200 ms for Sample Time Set
! Take a Measurement
µ
RF
Envelope
Trigger Level
(Int. or Ext.)